CN106293998A - A kind of system backup method based on snapping technique - Google Patents

Abstract

The invention discloses a kind of backup method based on snapping technique, the method is intended to main uses in backup procedure and is ensuring that the seriality of business, reaches the shortest recovery time and minimum amount of data lost (minimum RTO and RPO).Present invention will usually be used in computer data file, store, back up, remote disaster tolerance, in disaster recovery.

Description

A kind of system backup method based on snapping technique

Technical field

The present invention relates to a kind of system backup method based on snapping technique, belong to field of computer data processing

Background technology

Computer is used to carry out the demand of data storage in recent years increasing; raising along with storage application demand; user needs online mode to carry out data protection; snapshot is exactly one of effective ways of Online storage device strick precaution loss of data; in ten years in past, snapshot has become as the standard configuration function of disk array, volume manager, file system even PCI RAID (RAID) controller.Increasing equipment all starts to support this functionality.Increasing storage device supports snapshot functions, has publicized the advantage of respective snapping technique, have plenty of snapshot quantity many in the data of these products, have plenty of take up room little.

The definition of snapshot is by SNIA (storage networking industry association): about a completely available copy of appointment data acquisition system, and this copy includes the corresponding data reflection at certain time point (time point that copy starts).Snapshot can be a copy of its represented data, it is also possible to be a copy of data.And from the point of view of concrete ins and outs, snapshot is directed to the invoking marks of data or the pointer being saved in storage device.We are it is to be understood that snapshot is somewhat like being detailed catalogue listing, but it is treated as complete data backup by computer.

Snapshot has three kinds of primitive forms: based on file system formula, based on subsystem formula and based on volume manager/virtualization formula, and these three form difference is the biggest.Having occurred in that on market that the utility that can automatically generate these snapshots, the most representational storage device having NetApp realize based on file system, senior middle school's low side devices uses common operating system, can realize snapshot applications.

The effect of snapping technique: mainly can carry out online data recovery, can carry out timely data recovery when storage device generation application and trouble or file corruption, data reverts to snapshot and produces the state of time point.Another effect of snapshot is to provide another one data access channel for storage user, and when former data carry out application on site process, user can access snapshot data, it is also possible to utilizes snapshot to carry out the work such as test.Therefore, all storage systems, though senior middle school's low side, as long as being applied to on-line system, then snapshot just becomes an indispensable function.

Having two big class storage snapshots, one is called i.e. to write i.e. copies snapshot, and another kind is called segmentation mirror snapshot.

I.e. write and i.e. copy snapshot and can generate the snapshot to storage data change when every time input new data or data with existing are updated.Do so can promptly recover data when there is hard disk write error, file corruption or program mal.But, if need all data on network or storage medium are achieved completely or recovered, all snapshots in the past all must be available for using.I.e. writing and i.e. copying snapshot is performance data external appearance characteristic " photo ".This mode is also generally referred to as " metadata " copy, and the most all of data are not really copied to another position, and the pointer being only referred to registration present position, border factually is copied.In the case of using this technology, when there being snapshot, if one attempt to the data rewritten on original LUN, snapshot software, by first by new for original data block copy to position (be exclusively used in and replicate the memory resource pool operated), carries out write operation the most again.Later when you quote initial data, snapshot software by pointer maps to new position, or when you quote snapshot by pointer maps to old position.

Segmentation mirror snapshot quotes all data in mirror image hard disk groups.When every time application runs, all generate the snapshot of whole volume, and more than new data or the data of renewal.This make offline access data be possibly realized, and simplify recovery, replicate or achieve the process of all data on one piece of hard disk.But, this is a slower process, and each snapshot needs to take more memory space, is also called slavish copying, owing to it is the physical copy of the data in a certain LUN or file system, and some managers referred to as clone, reflection etc..The process of slavish copying can complete by main frame or on storage level with hardware.

Snapping technique using method: during specifically used snapshot, storage administrator can be there to be three kinds of forms, the coldest snap copy, warm snap copy and hot snap copy.

Cold snap copy: carry out cold snap copy and be to ensure that system can be in the safest mode being always completely recovered.Before and after carrying out any big configuration variation or maintenance process, it is typically necessary and carries out cold copy, to ensure to restore to the original state (rollback) completely.Cold copy can also combine with clone technology and replicate whole server system, and to realize various purpose, the duplicate such as extension, making production system is used and to two layers of storage migration for testing/developing.

Warm snap copy: warm snap copy utilizes the hang-up function of server.When performing to hang up action, program counter is stopped, and all of movable internal memory is all stored in the temporary file (.vmss file) in the file system guiding hard disk place, and device out of service application.On this time point, replicate the snap copy of whole server (including memory content file and all of LUN and relevant active file system).In this copies, machine and all of data are by process points when being frozen in pending operation.

When snapshot operation completes, server can be restarted, and resumes operation on the point that action starts hanging up.Application program and server process will be resumed operation from same time point.On the surface, just look like that to press a Pause key during snapshot activities the same.For server net computer apparently, just look like as network service has temporarily interrupted.For the server that appropriateness loads, during this period of time generally at 30 to 120 seconds.

Hot snap copy: in this state, all of write operation of generation is all immediately applied on an empty hard disk, to keep the concordance of the height of file system.Server provides the instrument allowing lasting virtual hard disk be in hot-standby mode, to replicate snap copy on the hard disk subsystem layer by interpolation REDO journal file.

Once REDO daily record is activated, and the snapshot of the copy package LUN containing server file system is safe.After snapshot operation completes, can send another order, REDO log processing is submitted to following virtual hard disk file by this order.When submission activity completes, all of journal entry all will be employed, and REDO file will be deleted.In performing this operating process, it may appear that the slightly decline of processing speed, but all of operation will continue executing with.But, as a rule, snapshot process almost moment completes, and the time between establishment and the submission of REDO is the shortest.

Hot snapshot operation process is the most substantially detectable rate server and declines.In worst case, it seems to be exactly that the general server speed that is likely to result in of the CPU of network congestion or overload declines.Under best-case, do not have the impact perceived.

Snapping technique-snapshot and mirror image, the difference of duplication

Mirror image, snapshot are three kinds of different functions with duplication

Mirror image is by replicating data from I/O two I/O of establishment.Disk mirroring is created on the master system by OS or volume management software.Disk mirroring is dependent on platform and the local option of local connection performance.Mirror image can be used for DAS and SAN and most of NAS supports it.Storage relay type mirrored disk subsystem (such as, EMC SRDF, IBM PPRC, Hitachi TrueCopy) is mainly used in SAN product.

Duplication is by transmitted data on network object (file, form etc.).Transmission carries out from system to system rather than carries out between storage device or between subsystem.Replicating typically also for platform specific, there is a great difference with Unix platform in the method for operation that thus be accordingly used in Windows 2000 replicated product.

Data snapshot technology in snapping technique-disaster tolerance technology

Remote Switched Port Analyzer technology often combines with snapping technique and realizes remote backup, i.e. by mirror image, data is backuped in remote storage system, then with snapping technique in the information back-up in remote storage system to long-range tape library, CD server.

Snapping technique is divided into two classes, a class pointer type, is quickly to be scanned the data of disk subsystem to be backed up by software, sets up snapshot LUN LU wanting Backup Data

Either produce, test, disaster recovery, or data warehouse applications, this system part external member can provide the generation of business datum image copies and management to safeguard, makes client utilize business datum the most more preferably, more fully, it is thus achieved that bigger value-rising.The copy management system part designed based on data duplication, protection and information sharing; provide the most powerful function: both can realize data between a data central interior or different pieces of information center and replicate; information sharing can also be realized between different departments; adapt to the flexible expansion of business quickly and efficiently, competition obtains leading superiority.It may use that family is in the case of regular traffic is unaffected, extract real-time currently online business datum.Its " backup window ", close to zero, can be greatly increased the seriality of system business, provides guarantee for 7 × 24 operatings realizing system real.

Summary of the invention

The present invention be directed to the backup method of the snapping technique utilized in backup procedure, to solve file at computer data, store, back up, remote disaster tolerance, disaster recovery Computer memory space utilization rate are low and reduce the probability that data deletion is judged by accident.

What the present invention proposed is that the backup measured step of snap shot comprises the following steps:

First, the basic module of a client was installed in the application service phase, adds a data filter just as to server

Secondly, when user is toward the when of writing data inside hard disk, it is to write, before being written to hard disk according to byte mode, filter has been known for the write value of data, is transferred to inside the storage pool of server by network in the case of not affecting the write IO of the period of service simultaneously.And the mode that data base writes hard disk is the rule according to oneself, in units of transaction, the mode of byte is written on hard disk, this time, data base is written to local disk and to be written to the mode inside storage pool completely the same, the writing mode of data base simulates data base's writing mode at local hard drive, this database simulation writing mode, it is ensured that the stric consistency of database data.Owing to the data of write CDP storage pool need not scan the database purchase hard disk of application server, but according to model identical, write direct CDP storage pool, so data syn-chronization is quick, more ensure that concordance and the integrity of business datum.

Accompanying drawing explanation

Fig. 1, backup mode figure based on snapping technique

Detailed description of the invention

The present invention is to propose the backup method of a kind of snapping technique, concrete data Stored Procedure

Its detailed step of said method can be divided into following a few step:

When user is while application system write data, also it is real-time transmitted to inside the storage pool of HeartsOne-CDP, the time (being such as 1 minute) that storage pool can set according to you automatically, these data in storage pool are done a snapshot, and user is it can be seen that the full dose data of each time point.And there is no the restriction of number.If the when of the loss of data of user or damage, directly recovering the snapshot data of up-to-date time point inside storage pool.

Claims (2)

1. a system backup method based on snapping technique, its step is as follows:

First, the basic module of a client is installed in the application service phase

Secondly, when user is toward the when of writing data inside hard disk, it is to write, before being written to hard disk according to byte mode, filter has been known for the write value of data, is transferred to inside the storage pool of server by network in the case of not affecting the write IO of the period of service simultaneously.And the mode that data base writes hard disk is the rule according to oneself, in units of transaction, the mode of byte is written on hard disk, this time, data base is written to local disk and to be written to the mode inside storage pool completely the same, the writing mode of data base simulates data base's writing mode at local hard drive, this database simulation writing mode, it is ensured that the stric consistency of database data.Owing to the data of write CDP storage pool need not scan the database purchase hard disk of application server, but according to model identical, write direct CDP storage pool, so data syn-chronization is quick, more ensure that concordance and the integrity of business datum.

2. the basic module in one client of application service phase installation as described in claim 1 its objective is as added a data filter to server.